The major aim of this laboratory is to use electron microscope techniques to correlate structure with normal and pathologically altered function of leukocytes and platelets. Work on platelets will primarily deal with the surface membrane and coat and the role these structures play in adhesion and aggregation. The interaction between collagen, proteoglycan and platelets will receive particular scrutiny not only because it may elucidate how modulation of external coat material may be transduced to the interior of the cell in platelets, but because the results obtained may explain analogous mechanisms operative in other cells being studied in this laboratory, e.g., transformation of normal lymphocytes vs. the impaired response of CLL cells, or the degranulation phenomenon in phagocytizing granulocytes. Our major thrust will be to combine the freeze-etch technique used to analyze intramembranous events with conjugated antibody methods employed to identify cell surface and submembranous alterations. Soft agar tissue culture will continue to be used for the analysis of abnormal hematopoiesis and for exploration of the relationship between stimulated T-lymphocytes and proliferation of eosinophils.